Brees hooked up with Jimmy Graham on a 44-yard touchdown and Benjamin Watson on a 1-yard scoring play, both in the first half and good enough to give the first-place Saints (9-2) a sweep of their season series with their NFC South rivals.

Atlanta (2-9) dropped its fifth straight game, clinched its first losing season since 2008 and was officially eliminated from the division race with five weeks remaining.

The Falcons had a chance to pull off the upset, driving to the Saints 29 with less than 3 minutes to go. But New Orleans turned up the pressure on Matt Ryan, Atlanta missed a long field goal, and the Saints ran off all but the last 5 seconds.

The Georgia Dome rocked with chants of “Who Dat! Who Dat!” as the final seconds ticked off the clock, the Saints ensuring they will remain alone atop the NFC South and just one game behind Seattle for home-field advantage throughout the NFC playoffs. New Orleans will face the Seahawks on Dec. 2 in what shapes up as one of the biggest games of the year.

The Falcons had hoped to salvage some bit of pride in this lost season, driving from their own 9 — actually, the 3 after Ryan was sacked — to the Saints 29. But Ryan was sacked again by Cameron Jordan and hurried into a pair of incompletions. As the crowd groaned, the Falcons surprisingly sent on Matt Bryant to attempt a 52-yard field goal.

He knocked one through, but the Saints called timeout just before the snap. After standing around during the commercial break, Bryant’s next try sailed wide of the left upright.

Brees and the offense took it from there, assuring Atlanta had time for only one desperate play at the end.

The Saints quarterback was 23 of 33 for 278 yards. Ryan was 30 of 39 for 297 yards, but Atlanta’s offense produced only one touchdown — the fourth time that has happened during the its current skid.

The Falcons, who had been outscored 135-61 over their previous four games, put together an impressive drive on their opening possession. Steven Jackson carried it five times for 24 yards, the last of them a dive into the end zone on third-and-goal at the Saints 1. The touchdown came after Darius Johnson appeared to score on a quick slant, but the replay showed a knee was down just before he stuck the ball over the goal line.

Jackson’s TD on the next play gave Atlanta its first lead in nearly a month. The Falcons had gone nearly 15 quarters — almost four full games — since being up 3-0 over Arizona early in Week 8.

The advantage didn’t last long. Brees guided a 15-play, 78-yard drive in which the Saints converted five straight times on third down, including Watson’s leaping catch in the back of the end zone.

Bryant put the Falcons back ahead with the first of his two field goals, a 39-yarder early in the second quarter, but New Orleans grabbed the lead for good when Graham slipped behind the secondary and hauled in his long touchdown.

He celebrated by dunking over the goalpost and hung on the crossbar for extra emphasis, actually bending the post. As the Saints lined up to attempt the extra point, the officials noticed the crooked uprights, leading to a brief delay as a worker on a ladder came out to straighten the bar.

The Falcons got in position to recapture the lead, driving to the New Orleans 10. On third-and-goal, Ryan couldn’t find an open receiver and took off running, briefly spotting a clear path to the end zone. But the Saints closed in quickly, prompting Ryan to slide down at the 6 rather than risk an injury. Some Atlanta fans booed as Matty Ice trotted off the field, no doubt remembering a college game the previous week when Georgia quarterback Aaron Murray fearlessly plowed straight ahead to score a touchdown in the closing seconds against Auburn.

Atlanta settled for another Bryant field goal from 24 yards and trailed 14-13 at the half.

The Falcons got no closer.

The only points of the second half came on Garrett Hartley’s 41-yard field goal for the Saints.